<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
<script>
    var WGS84_to_GCJ02 = function() {}
    WGS84_to_GCJ02.prototype.a = 6378245.0;
    WGS84_to_GCJ02.prototype.ee = 0.00669342162296594323;
    WGS84_to_GCJ02.prototype.transform = function(wgLat, wgLon) {
        if (this.outOfChina(wgLat, wgLon)) {
            return [wgLat, wgLon];
        }
        dLat = this.transformLat(wgLon - 105.0, wgLat - 35.0);
        dLon = this.transformLon(wgLon - 105.0, wgLat - 35.0);
        radLat = wgLat / 180.0 * Math.PI;
        magic = Math.sin(radLat);
        magic = 1 - this.ee * magic * magic;
        sqrtMagic = Math.sqrt(magic);
        dLat = (dLat * 180.0) / ((this.a * (1 - this.ee)) / (magic * sqrtMagic) * Math.PI);
        dLon = (dLon * 180.0) / (this.a / sqrtMagic * Math.cos(radLat) * Math.PI);
        mgLat = wgLat + dLat;
        mgLon = wgLon + dLon;
        return [mgLat, mgLon];
    };
    WGS84_to_GCJ02.prototype.outOfChina = function(lat, lon) {
        if (lon < 72.004 || lon > 137.8347)
            return true;
        if (lat < 0.8293 || lat > 55.8271)
            return true;
        return false;
    };
    WGS84_to_GCJ02.prototype.transformLat = function(x, y) {
        var ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
        ret += (20.0 * Math.sin(6.0 * x * Math.PI) + 20.0 * Math.sin(2.0 * x * Math.PI)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(y * Math.PI) + 40.0 * Math.sin(y / 3.0 * Math.PI)) * 2.0 / 3.0;
        ret += (160.0 * Math.sin(y / 12.0 * Math.PI) + 320 * Math.sin(y * Math.PI / 30.0)) * 2.0 / 3.0;
        return ret;
    };
    WGS84_to_GCJ02.prototype.transformLon = function(x, y) {
        var ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
        ret += (20.0 * Math.sin(6.0 * x * Math.PI) + 20.0 * Math.sin(2.0 * x * Math.PI)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(x * Math.PI) + 40.0 * Math.sin(x / 3.0 * Math.PI)) * 2.0 / 3.0;
        ret += (150.0 * Math.sin(x / 12.0 * Math.PI) + 300.0 * Math.sin(x / 30.0 * Math.PI)) * 2.0 / 3.0;
        return ret;
    };
    //116.481499,39.990475|116.481499,39.990375
    //116.487585177952,39.991754014757;116.487585177952,39.991653917101
   console.log("answer",[116.487585177952,39.991754014757])
    let zuobiao = new WGS84_to_GCJ02().transform(39.990475, 116.481499);
    console.log('WGS-84转为GCJ-02坐标',zuobiao)
    var GPS = {
        PI: 3.14159265358979324,
        x_pi: 3.14159265358979324 * 3000.0 / 180.0,
        transformLat: function(x, y) {
            var ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x))
            ret += (20.0 * Math.sin(6.0 * x * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0
            ret += (20.0 * Math.sin(y * this.PI) + 40.0 * Math.sin(y / 3.0 * this.PI)) * 2.0 / 3.0
            ret += (160.0 * Math.sin(y / 12.0 * this.PI) + 320 * Math.sin(y * this.PI / 30.0)) * 2.0 / 3.0
            return ret
        },
        transformLon: function(x, y) {
            var ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x))
            ret += (20.0 * Math.sin(6.0 * x * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0
            ret += (20.0 * Math.sin(x * this.PI) + 40.0 * Math.sin(x / 3.0 * this.PI)) * 2.0 / 3.0
            ret += (150.0 * Math.sin(x / 12.0 * this.PI) + 300.0 * Math.sin(x / 30.0 * this.PI)) * 2.0 / 3.0
            return ret
        },
// 坐标转换
        delta: function(lat, lon) {
            var a = 6378245.0 // a: 卫星椭球坐标投影到平面地图坐标系的投影因子。
            var ee = 0.00669342162296594323 // ee: 椭球的偏心率。
            var dLat = this.transformLat(lon - 105.0, lat - 35.0)
            var dLon = this.transformLon(lon - 105.0, lat - 35.0)
            var radLat = lat / 180.0 * this.PI
            var magic = Math.sin(radLat)
            magic = 1 - ee * magic * magic
            var sqrtMagic = Math.sqrt(magic)
            dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * this.PI)
            dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * this.PI)
            return { 'lat': dLat, 'lon': dLon }
        },
// 判断是否为国外坐标
        outOfChina: function(lat, lon) {
            if (lon < 72.004 || lon > 137.8347) { return true }
            if (lat < 0.8293 || lat > 55.8271) { return true }
            return false
        },
// GPS---高德
        gcj_encrypt: function(wgsLat, wgsLon) {
            if (this.outOfChina(wgsLat, wgsLon)) { return { 'lat': wgsLat, 'lon': wgsLon } }
            var d = this.delta(wgsLat, wgsLon)
            return { 'lat': wgsLat + d.lat, 'lon': wgsLon + d.lon }
        }
    }
    console.log(GPS.gcj_encrypt(39.990475, 116.481499))
</script>
</body>
</html>
